Plastic containers with covers have become quite popular for storing items, particularly, for example, foodstuffs. As such, it is particularly important that there be a tight seal between the container base and the cover. U.S. Pat. No. 4,471,880 discloses a very popular version of such a container with a tight seal. In fact, the seal afforded by this patented concept is so good that it is often difficult to break the seal and remove the cover from the container.
Oftentimes, a small, generally horizontally-oriented tab is provided on the cover which is intended to be grasped and pulled upwardly by the user to break the seal. Such are often too small to provide the user with a sufficient grip to apply sufficient force to break the seal. Even making the tabs larger is not a feasible solution: first, because more lateral space is undesirably utilized, and, second, because only a generally vertical force is still applied, which force is not the ideal force for breaking the seal. Rather, a horizontal force moment applied to the outer periphery of the cover is more desirable to break the seal afforded by the concept of U.S. Pat. No. 4,471,880.
As a result, covers have recently been designed which have one or more downturned flaps that are elongate in nature to form a vertically-oriented lever. As a flap is flexed outwardly, a horizontal force moment is exerted on the periphery of the cover to break the seal with far less force that was required with the previously utilized horizontal tabs. In fact, even the youngest or oldest of users can readily break the airtight seal utilizing these flaps.
For round containers, usually one circumferentially-located flap will suffice. However, for rectangular or square containers, a flap positioned along any of the four sides is usually not sufficient for easy cover removal. Rather, the flap or flaps are preferably positioned at a corner or corners and usually extend a fairly substantial distance along the sides forming the corner. As such, the lever opening force is distributed along the two sides forming the corner and the seal is more readily broken.
The only major problem with the covers with these flaps is that they cannot readily be used with rectangular containers having conventionally-positioned handles. That is, quite often, particularly for larger containers, handles which extend outwardly from near the top of the container base are provided to assist in transporting the containers, which is especially important when hot items are contained therein. The traditional location for such handles on a rectangular container is on the opposed shorter sides. However, the flap on the cover will interfere with the handles and thus such covers cannot be utilized with conventional rectangular containers.
While the existence of the handles does not prohibit the nesting of the containers which is desirable for purposes of economic shipment, storage, retail display and the like, in containers which have internal walls which divide the container into compartments, such nesting is normally impractical, if not impossible, because of the interference of the dividing walls. Thus, the need exists for a divided, rectangular container which can nest within a like container.